[ 'exception', ], 'only argument is null reference' => [ '#VALUE!', null, ], // Boolean TRUE and NULL [ true, true, null, ], // Boolean FALSE and NULL [ false, false, null, ], // Both TRUE Booleans [ true, true, true, ], // Mixed Booleans [ true, true, false, ], // Mixed Booleans [ true, false, true, ], // Both FALSE Booleans [ false, false, false, ], // Multiple Mixed Booleans [ true, true, true, false, ], // Multiple TRUE Booleans [ true, true, true, true, ], // Multiple FALSE Booleans [ false, false, false, false, false, ], [ true, -1, -2, ], [ false, 0, 0, ], [ true, 0, 1, ], [ true, 1, 1, ], 'string 1 is ignored' => [ false, 0, '1', ], 'true string is ignored' => [ true, 'TRUE', 1, ], 'false string is ignored' => [ true, 'FALSE', true, ], 'non-boolean string is ignored' => [ true, 'ABCD', 1, ], [ true, -2, 1, ], [ true, -2, 0, ], ];